I'm surprised he doesn't mention real estate or investing in friend/family businesses as an option.
This isn't as safe as index funds, but it is an option where you can increase your success rate by being competent. It probably has a risk profile similar to working for equity at a startup, an option only available to people who work in or around startups.
He also didn't mention putting your money in TSP if you're an eligible federal employee, or talk about individual 401ks tied to an LLC to increase retirement saving limits, or why wandering the halls of Google makes you predisposed to think Cisco would be a no-way-to-lose investment. The article represents a smart but narrow dude's perspective on a very, very big world.
That said, Real Estate during the "banks won't loan anyone money and interest rates are headed up storm" and "loan money to friends/family in the Shark Tank era" don't make my "top wealth-building picks" list for 2015...
This isn't as safe as index funds, but it is an option where you can increase your success rate by being competent. It probably has a risk profile similar to working for equity at a startup, an option only available to people who work in or around startups.